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Alx Ki
Python Web Development Techdegree Graduate 14,822 PointsWriting script for creating model instances from json.
I got stuck with 6th project trying to create model instances for each mineral in json.
In django docs i found info about creating classmethods for this purpose. so I did (without exception for updating just to test):
class Mineral(models.Model):
name = models.CharField(max_length=100, unique=True)
image_filename = models.CharField(max_length=255)
image_caption = models.CharField(max_length=255)
category = models.CharField(max_length=255)
formula = models.CharField(max_length=255)
strunz_classification = models.CharField(max_length=255)
crystal_system = models.CharField(max_length=255)
unit_cell = models.CharField(max_length=255)
color = models.CharField(max_length=255)
crystal_symmetry = models.CharField(max_length=255)
cleavage = models.CharField(max_length=255)
mohs_scale_hardness = models.CharField(max_length=255)
luster = models.CharField(max_length=255)
streak = models.CharField(max_length=255)
diaphaneity = models.CharField(max_length=255)
optical_properties = models.CharField(max_length=255)
refractive_index = models.CharField(max_length=255)
crystal_habit = models.CharField(max_length=255)
specific_gravity = models.CharField(max_length=255)
def __str__(self):
return self.name
@classmethod
def add_minerals_to_database(cls):
with open('minerals.json', encoding='utf8') as file:
all_of_them = json.load(file)
for each in all_of_them:
Mineral(
name=each['name'],
image_filename=each['image filename'],
image_caption=each['image caption'],
category=each['category'],
formula=each['formula'],
strunz_classification=each['strunz classification'],
crystal_system=each['crystal system'],
unit_cell=each['unit cell'],
color=each['color'],
crystal_symmetry=each['crystal symmetry'],
cleavage=each['cleavage'],
mohs_scale_hardness=each['mohs scale hardness'],
luster=each['luster'],
streak=each['streak'],
diaphaneity=each['diaphaneity'],
optical_properties=each['optical properties'],
refractive_index=each['refractive index'],
crystal_habit=each['crystal habit'],
specific_gravity=each['specific gravity']
).save()
But how and where(!) to use it?? I can't just run models.py, and all I found on StackOverFlow is for old Django versions and doesn't work. Update: I'm pretty shure you know how it works, Tatiana Vasilevskaya , so if you have a minute or two, i'd appreciate that! Kenneth Love , I need your help!)
3 Answers
Kenneth Love
Treehouse Guest TeacherIf you want to click a button to make it happen, that would require a view, wouldn't it?
If you want it to be automatic, I'd probably look at using a data migration.
jacinator
11,936 PointsIf you run python manage.py shell from the directory with your manage.py file that will launch a shell. From that shell you can from <app-name>.models import Mineral. Then you can call the method.
Alx Ki
Python Web Development Techdegree Graduate 14,822 Pointsjacinator I know that way, but I want a href on my site, like a button "get info from json to database" You click it and the magic happens!)
Tatiana Vasilevskaya
Python Web Development Techdegree Graduate 28,600 PointsAs far as I remember the task explicitly asks to write a script that populates a database from json data, which could be a migration as Kenneth suggested or a separate script that reads a json file, creates Mineral instances and saves into the database. If you want, you can check my script.
Alx Ki
Python Web Development Techdegree Graduate 14,822 PointsNow trying to build a separate script. Thank you! I'll surely take a look at your script but only after mine is done)) Just want to make it myself.
Alx Ki
Python Web Development Techdegree Graduate 14,822 PointsAlx Ki
Python Web Development Techdegree Graduate 14,822 PointsI understand that it needs a view, Idon't understand how the script gets to db, I mean we only did it from shell. how does the script get to the manage.py shell or doesn't it need the shell?
i wrote a file:
(Found thing about settings on stackoverflow, don't really know if it's right)
It doesn't work, because, i guess, db is not initialized or smth.
Kenneth Love
Treehouse Guest TeacherKenneth Love
Treehouse Guest TeacherIt would be a view just like all of the other views you've created. Something along the lines of:
The first
...is your existing bit where you load the minerals from the JSON file. The second is where you fill in the details of the mineral.Alx Ki
Python Web Development Techdegree Graduate 14,822 PointsAlx Ki
Python Web Development Techdegree Graduate 14,822 PointsThank you, Kenneth Love. Somewhy it took me long to understand how to access a db with django after flask and peewee..
Now db updates automatically each time you access main page! (What if new minerals appear!)